11 August 2008

Some of you might have had this problem in the past, you know that your network working perfectly yet suddenly its not working and only showing ip address 169.254.X.X where X can be 0 to 255.

This can happen if you use DHCP in your network. What happen is that the computer set as DHCP client will search for DHCP server and when it can't find the server it will automatically assign ip address of 169.254.X.X. This is actually called APIPA (Automatic Private IP Addressing).

In case of Vista, it will search for DHCP server for about 6 seconds and then assign the APIPA, it will continuously search the server afterward - or so they say.
There are several ways to solve this problem:
First thing to try is renew the ip of the client, use the following commands in the command prompt.
Note: You can find the command prompt at the Start menu > Run and then type cmd and press enter.

ipconfig /release

ipconfig /renew

Now this is rarely solve the problem because chances are that you have a networking equipment problem. If the above step not working, try shutdown all the networking devices, leave it be for about 30 seconds and start them in the following order:

Cable/DSL Modem - Router - Switch - Computer clients.

Perhaps the problem even at the cables, try using other cable for your connectivity.

The last resort is to reset the TCP/IP stack in your client. Sometimes the TCP/IP stack gets corrupted/damaged and you need to reset using the following commands at the command prompt: